Myxini & Cephalaspidomorphi
- 1. Class: Myxini & Cephalaspidomorphi Phylum Chordata Subphylum Vertebrata Michele Rudolph Period 2
- 2. To introduce myself… Hey! I’m just your average jawless vertebrate (but no creepy eel!), with what is considered to be the most primitive living vertebrate body plan. I’m a pioneer in my own right, setting the stage for the subphylum Vertebrata. My most exciting trait? I’ll ooze slime onto any predator ready to attack! I’m also a great scavenger– I can help you find a great dinner from the bottom of the ocean!
- 3. Home Sweet Home Hagfish (Myxini) Bottom of the ocean Mostly cold waters A place with little need for me to osmo- or thermoregulate. A place with lots of dead/sick fish, worms, or other bottom-dwelling food sources to scavenge. Lamprey (Cephalospidomorphi) Marine or freshwater environment North America (USA/Canada) & places with similar climates A place with easy access to suspension feeding
- 4. Favorite Pastimes Hagfish Covering potential predators with incredible amounts of disgusting slime Scavenging the bottom of the ocean for tasty dead animals Swimming like a snake through the ocean Lamprey Grabbing onto prey with my mouth, sticking in my tongue, and sucking their blood Being a general parasite and nuisance Migration to the sea– the true meaning of being an adult
- 5. Evolutionary Advancements Hagfish The most primitive living vertebrates (not a true vertebrate. A partial cranium. A skeleton made entirely of cartilage. A notochord for support—aiding in movement and structure for muscles. Lamprey The first class with a vertebral column (a notochord with a cartilage surrounding & vertebral projections). A complete braincase.
- 6. Special Features Hagfish Slime secretions upon contact with predators Cartilage skeleton Partial cranium “ Direct development”- no larval stage Sensory organs on head Bilateral symmetry- no paired appendages Can change gender according to season Coelomate Gills Two chambered heart with aortic arches Triploblastic Lamprey A round mouth with “teeth” and a “tongue” One nostril A complete cranium Rudimentary vertebrae Suspension feeders as larvae, parasites as adults Bilateral symmetry- no paired appendages Coelomate Gills Triploblastic Osmoregulation through gills
- 7. I’m seeking… Someone willing to swim around like a snake/eel all day Someone easygoing, who will eat anything and tolerate numerous slime secretions and accidental blood losses Someone to simply fit my life cycle– which, according to evolution, isn’t really going to change!